This project continues an established, multiphasic study of the nature, levels and human health impact of airborne allergen exposure. We will study prevalence patterns of basidiospores, ascospores and selected imperfect fungi, using microscopy and culture of volumetric collections and will design and test assay methods based on ELISA inhibition and on fluorescent staining with monoclonal reagents. Human Type 1 responses to previously unstudied spores will be examined by skin and mucosal provocative tests as well as ELISA and ELISA inhibition. The latter aproaches also will be used to study cross reactivity among fungus spore and pollen types with special emphasis on infrageneric allergen similarities. Late reactivity to some basidiospore preparations will be analyzed using measures of cell-mediated immunity (viz., lymphocyte transformation, lymphocyte inhibition factor production) as well as of humoral response (viz., IgE and IgG ELISA, leucocyte histamine release). The extent of such responses to more commonly recognized fungal agents also will be examined. The effectiveness of portable air cleaners for removal of allergenic particulates will be assessed objectively in replicate treated and untreated rooms. In related studies, various protective masking procedures will be compared for specifically sensitive persons exposed to animal-derived aerosols; nasal and bronchial patency parameters will be utilized. Exposures incident to grass cutting and various turf practices will be assessed quantitatively by culture, direct microscopy and assay of amorphous allergens as well as bacterial endotoxins. Finally, a range of collection aproaches will be compared to identify relatively low cost methods for assessing indoor microbial burdens.